Angelov A, Stomonyakov V, Boev M
Acta Physiol Pharmacol Bulg. 1976;2(2):10-9.
The changes in the late positive wave P3 of the averaged evoked potentials (AEP) are studied under conditions when: (a) only high tones were presented requiring no motor response; (b) only low tones were presented requiring motor response; (c) the subject was instructed that the two types of tones will be presented in random order with a definite probability (50%:50% or 25%:75%, or conversely 75%:25%) requiring motor response only to the low tones. In fact, however, only high tones were presented to which no motor response was required (pseudo-mixed series). It has been established that under the effect of the verbal instruction used, the P3 wave of the AEP of the pseudo-mixed series increased at the beginning of the series, and thereafter the P3 "behaviour" was different with the different subjects: (1) In some of them P3 persisted until the presentation of a definite number of signals (different for the individual subjects) and afterwards it disappeared; (2) In some others P3 now increased now disappeared in a manner different for the different subjects; (3) Subjects in which P3 remained pronounced throughout the entire series; they also "heard" low tones. All these changes in P3 did not depend on the probability characteristics of the pseudo-mixed series ascribed by the instruction. The dependence of the late positive wave P3 on the processes of probability prediction in the human brain functioning, and on the changes in the arousal, is discussed.
在以下条件下研究平均诱发电位（AEP）的晚期正波P3的变化：（a）仅呈现高音，无需运动反应；（b）仅呈现低音，需要运动反应；（c）指示受试者两种类型的音调将以一定概率（50%:50%或25%:75%，或反之75%:25%）随机呈现，仅对低音需要运动反应。然而，实际上只呈现了不需要运动反应的高音（伪混合系列）。已经确定，在所用言语指令的作用下，伪混合系列AEP的P3波在系列开始时增加，此后不同受试者的P3“表现”不同：（1）其中一些受试者的P3持续到呈现一定数量的信号（个体受试者不同），然后消失；（2）另一些受试者的P3时而增加时而消失，不同受试者的方式不同；（3）在整个系列中P3一直很明显的受试者；他们也“听到”了低音。P3的所有这些变化并不取决于指令赋予的伪混合系列的概率特征。讨论了晚期正波P3对人脑功能中概率预测过程以及觉醒变化的依赖性。
